This invention relates to frequency converters generally and, more particularly, to a novel AC frequency converter having a higher efficiency and a lower weight/rating ratio than conventional frequency converters.
There are a number of situations where it is desirable to convert AC power at one frequency to AC power at a lower frequency. For example, most aircraft and some ground-based installations have only 400-450Hz AC electric power available for operation of computer and control instruments. This situation results from the optimization of generator size to give satisfactory power characteristics while minimizing the weight and size of the on-board generators. While these generators satisfactorily service those applications for which they are designed, there are a number of scientific and commercial devices that are designed to be powered only by 50-60 Hz sources. When these are to be used where only the higher frequency power is available, it is necessary to provide means to convert the 400-450 Hz power to 50-60 Hz in order to accommodate such scientific and commercial devices.
Known prior art converters to provide such frequency conversion operate by first rectifying the AC power to DC power and then driving an oscillator unit to provide the desired frequency. These converters serve their intended functions, but are relatively costly to manufacture and are relatively large in size and heavy in weight.
It is, therefore, an object of the present invention to provide a frequency converter that is relatively economical to manufacture.
It is another object of the invention to provide a frequency converter that is relatively small in size and light in weight for a given rating.
It is an additional object of the invention to provide a frequency converter that can convert 400-450 Hz AC power to 50-55 Hz AC power.